Ages ago, there was TextPad -- a commercial product. Back when I was munging textified order histories for a multinational (lots of orders, ergo huge text files), it was great up through version... 4.7.3, I seem to recall. Then, they started redesigning some things in ways I found enworsening (if I may be permitted to riff off of the current linguistic trend). But, IIRC, it remained fast with big files.
This all was 20+ years ago. I wonder whether they're still around...
This all was 20+ years ago. I wonder whether they're still around...
https://www.textpad.com/home